In sending Scud missiles to Hezbollah in Lebanon, Syria may trigger a Syrian-Israeli- Lebanese war. You can thank several years of Western “outreach” to Syrian President Bashar Assad.

Such a conflict would trash hopes for renewed Palestinian-Israeli negotiations and international sanctions on Iran — President Obama’s regional goals. Yet Obama’s penchant for “engagement” has played a vital role in Assad’s remarkable transformation from the Mideast’s loneliest player to its cockiest.

US sources have confirmed the news broken last week by Israeli President Shimon Peres, who said in Paris that even while Syria talks of peace, it’s sending Scuds to Hezbollah. With a range of 435 miles, the missiles are a significant addition to Hezbollah’s known arsenal: During the 2006 Lebanon war, the terror group could only hit northern Israeli towns; with the Scuds, it can reach all of Israel’s populated areas.

Israel reportedly mulled bombing a recent convoy carrying the missiles from Syria to Lebanon, but decided against it — for now. But Jerusalem is unlikely to permit Hezbollah to possess arms that threaten every man, woman and child in Israel, complicating any military plan for ending the far greater threat of an Iranian nuclear bomb.

Using intermediaries, Jerusalem sent warnings to Damascus. So did Washington: Sen. John Kerry expressed concerns about weapons transfers to Hezbollah during a Damascus visit in early April. An American UN diplomat, Alejandro Wolff, publicly told the Security Council last week that the United States is concerned about the “sophistication” of the weapons Syria’s giving Hezbollah — which, he said, “risks sparking a conflict that no one needs.”

Why has Assad grown so brazen? Go back to the fall of 2008, when Hezbollah took Beirut over by force, signaling that Lebanon’s pro-Western, anti-Syrian governing coalition was a mere paper tiger. Hezbollah quickly withdrew its soldiers, but then its politicians joined the government, where they now have the power to veto any decision.

Meanwhile, the UN investigation into the 2005 Rafik Hariri assassination seemed stalled. The Assad regime, which for a while felt threatened by a possible prosecution of top aides for involvement in the killing the former Lebanese prime minister, could breath easier.

Powers that had shunned the Syrian regime started rushing to kiss Assad’s ring: The new French president, the Saudi king — even an array of formerly independence-minded Lebanese politicians — started showing up in Damascus almost daily.

In Washington, Secretary of State Condoleezza Rice also advocated a thaw in relations with Syria, but couldn’t muster much of a change in the waning days of the Bush presidency. But the new administration took up the cause, as Obama’s emissaries to Damascus started hinting that America would soon lift sanctions, and that other goodies were on the way. And in February came word that Washington would be sending a new ambassador to Syria, a job that America had pointedly left vacant since the Hariri killing.

The hope in all this is to wean Assad away from Iran and end his support for Hezbollah. Yet Assad “answered” the announcement of the new US ambassador by immediately inviting President Mahmoud Ahmadinejad for a visit and pulling Hezbollah’s leader, Hassan Nasrallah, out of hiding. The three publicly vowed that no outsider can break their military bonds, and the Syrian ruler explicitly mocked Secretary of State Hillary Clinton.

Evidently, sticks get Assad’s attention far better than carrots. Surrounded by advisers who are disconnected from much of the rest of the world, he tends to buy his own (highly inflated) rhetoric. With no outsiders giving him any reason to fear his behavior will come back to hurt him, he simply keeps demanding more concessions.

But the sticks may be returning to US diplomacy. Last week, Wolff hinted at the UN that the trial of the Hariri assassination could still come back to haunt Assad. America won’t use the UN court “as a bargaining chip” with Syria, he said.

At least some in the Obama administration understand now that the unconditional love poured on Assad has left him feeling invulnerable. What’s needed now is something to make it plain to him that he won’t be spared if he plays with fire. Let’s hope that comes in time to stop a war.beavni@gmail.com